U.S. 'laughing gas' emissions cause concern

Emissions of nitrous oxide ('laughing gas') generated from agriculture in the U.S. has been underestimated by 40 percent, according to a recent study.

Nitrous oxide is a chemical compound, formed from the oxidation of nitrogen. It is sometimes dubbed "laughing gas" because of its use in surgery and dentistry, for both anaesthetic and analgesic reasons. It also produces a euphoric effects on inhalation, making an illegal drug of concern especially associated with club culture.

The gas is also a significant greenhouse gas and air pollutant. Here it is, on the basis of mass, 300 times more dangerous to the environment than carbon dioxide.

In terms of the main sources in the environment, the gas is most closely associated with farming. Here, intensive farming together with the use of fertilizers are the main contributors. Although there has long been concern about the contribution that farming makes to air pollution, a new report suggests that the estimated levels have been miscalculated.

In a new study, the BBC reports that University of Minnesota scientists have looked at the U.S. corn belt region representing some 60 million hectares. With the study soil, rivers and streams were assessed for nitrogen build-up. Previous studies had previously only looked at soil. By expanding this to water the researchers found a nine fold underestimation.

The researchers think that similar underestimations have occurred in other industrialized countries like China, meaning that a different global perspective is required. Should this be borne out, alternative environmental controls could be required.

The research has been published in the journal Proceedings of the National Academy of Sciences. The paper is headed "Indirect nitrous oxide emissions from streams within the US Corn Belt scale with stream order."